JPH0884218A - Ccd color linear solid-state image pickup device - Google Patents

Abstract

PURPOSE: To suppress the occurrence of color slurring even when an original is read while its information is thinned out in the subscanning direction by selecting a pitch of picture element rows of three rows of light emitting sections to be a multiple of six of the picture element pitch of the light receiving section in the main scanning direction. CONSTITUTION: An image reflected from an original is formed on a CCD through a reduction lens whose magnification factor is A. As soon as a Y coordinate Yi on the original is read by a light receiving section R, a light receiving section G reads a Y coordinate Yk(=Yi+6×A×P) and a light receiving section B reads a Y coordinate Yj(=Yi+2×A×P). After the original is fed by 2 lines, that is, 2×A×P in the subscanning direction, the light receiving section R reads Yi+2(=Yi+2×A×P) and the light receiving section G reads Yi+2(=Yi+8×A×P) and the light receiving section B reads Yi+2(=Yi+14×A×P). When the original is fed further by 2 lines, the light receiving sections R, G, B read respectively Yi+4(=Yi+4×A×P),Yj+4(=Yi+10×A×P) and Yk+4(=Yi+16×A×P), then the Y coordinate group read by the light receiving sections is Yi+A×P×2×n, that is identical to each other, and then no color slurring takes place.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CCD color linear solid-state image pickup device used in a color scanner, a color copying machine or the like.

[0002]

2. Description of the Related Art In recent years, with the spread of color scanners, color copying machines, and the like, demand for CCD color linear solid-state image pickup devices has increased, and improvements in the characteristics thereof have been demanded. Various devices have been proposed to meet these demands. There is.

A conventional device will be described below with reference to the drawings. FIG. 3 shows a configuration example on a CCD of a conventional CCD color linear solid-state image pickup device.
Reference numeral B denotes a light receiving portion which is formed in parallel with the main scanning direction X and which has red, green and blue filters formed, respectively. When the pixel pitch in the main scanning direction of the three rows of light receiving portions is P, the line distance DRG between the light receiving portions R and G in the sub scanning direction Y, and the line spacing between the light receiving portions G and B in the sub scanning direction Y. The distance DGB is an integral multiple of P and can be expressed by (Equation 1).

[0004]

[Formula 1] DRG = nRG × P, DGB = nGB × P (nRG, nG
(B is an integer) Next, in order to explain the operation of the above-mentioned conventional example, first, in the CCD color linear solid-state imaging device configured as described above,
The reflected image of the read document shown in FIG. 2 irradiated with light is formed on the CCD using a reduction lens of magnification A. In FIG. 2, the main scanning direction is X, the sub scanning direction is Y, and the Y coordinate on the document is Ym.

In this way, a specific row i in the main scanning direction of the original, that is, the Y coordinate Yi on the original is read by the light receiving portion R having a red filter. At the same time, a specific row j in the main scanning direction, that is, the Y coordinate Yj on the original is read by the light receiving unit G having a green filter, and a specific row k in the main scanning direction, that is, the Y coordinate Yk on the original is blue. The light receiving unit B having the filter of No. 2 reads. The data read by the light receiving units of these three rows is written in the storage device.

Here, the reflected image of the original is passed through a reduction lens having a magnification of A, and the CCD of a CCD color linear solid-state image pickup device is used.
Since the image is formed on the upper side, the distance Yi− between the Y coordinate Yi on the original read by the light receiving unit R formed with the red filter and the Y coordinate Yj on the original read by the light receiving unit G formed with the green filter. There is a relationship of (Equation 2) between Yj and the inter-row distance DRG of the light receiving portion R and the light receiving portion G on the CCD of the CCD color linear solid-state imaging device in the sub scanning direction Y.

[0007]

## EQU00002 ## Yi-Yj = A.times.DRG Similarly, the Y coordinate Yj on the original read by the light receiving portion G formed with the green filter and the Y coordinate Yk on the original read by the light receiving portion B formed with the blue filter. Distance Yj-Yk and C
The light receiving portion G and the light receiving portion B on the CCD of the CD color linear solid-state imaging device have a relationship of (Equation 3) between the line spacing DGB in the sub-scanning direction Y.

[0008]

## EQU00003 ## Yj-Yk = A.times.DGB Next, after the original is fed by one line in the sub-scanning direction, that is, by the distance A.times.P, one specific line in the main scanning direction i + 1,
That is, the Y-coordinate Yi + 1 = Yi + A × P on the original is read by the light receiving unit R having a red filter. At the same time, a specific row j + 1 in the main scanning direction, that is, the Y coordinate Yj + 1 on the original document
= Yj + A × P = Yi + A × DRG + A × P = Yi + A × (DRG
+ P) = Yi + A × P × (nRG + 1) is read by the light receiving unit G having a green filter, and a specific one row k in the main scanning direction is read.
+1, that is, the Y coordinate on the document Yk + 1 = Yk + A × P = Y
i + A x (DRG + DGB) + A x P = Yi + A x P x (nRG +
nGB + 1) is read by the light receiving unit B having a blue filter. The data read by the light receiving units of these three rows is written in the storage device.

By sequentially performing the paper feeding operation line by line in this manner, the Y coordinate group on the original read by the light receiving unit R formed with the red filter is Yi + A × P × n (n is an integer) and green. The Y coordinate group on the original read by the light receiving unit G having the filter is Yj + A × P × n ₁ = Yi + A × (DRG +
P × n ₁ ) = Yi + A × P × n (n ₁ is an integer), and the Y coordinate group on the document read by the light receiving unit B having a blue filter is Y
k + A × P × n ₂ = Yi + A × (DRG + DGB + P × n ₂ ) = Y
i + A × P × n ( n 2 is an integer) the same Y coordinate group on next original R, G, the light receiving portion of the three colors of B is read.

Since these data are written in the storage device, one specific row of R, G, B3 on the document is read.
It is possible to read the data written in the light receiving units of the same type at the same time and perform signal processing, and it is possible to correct the time lag when reading the originals of the three types of light receiving units. In this way, the entire surface of the original is read by the CCD color linear solid-state imaging device. Hereinafter, in order to simplify the description, description of the data writing / reading operation to / from the storage device is omitted.

Next, a description will be given of the operation when the original is read while being thinned out in the sub-scanning direction, and the operation for reducing the resolution in the sub-scanning direction is performed, for example, when the original is thinned twice.

First, in the main scanning direction of the original, a specific row i, that is, the Y coordinate Yi on the original is read by the light receiving portion R having a red filter, and at the same time, a specific row j in the main scanning direction, that is, The Y-coordinate Yj on the original is read by the light-receiving unit G having a green filter, and a specific row k in the main scanning direction, that is, the Y-coordinate Yk on the original is read by the light-receiving unit B having a blue filter. In the sub-scanning direction of the document, the paper is fed by two lines, that is, a distance of 2 × A × P, and then one specific line i + 2 in the main scanning direction of the document, that is, the Y coordinate Yi + 2 = Yi + 2 × A × on the document. At the same time that P is read by the light receiving unit R having a red filter, a specific one row j + 2 in the main scanning direction, that is, Y coordinate Yj + 2 =
Yj + 2 × A × P is a light receiving portion G formed with a green filter
Is read, and a specific one row k + 2 in the main scanning direction, that is, the Y coordinate Yk + 2 = Yk + 2 * A * P on the document is read by the light receiving unit B having a blue filter.

After feeding the original by two lines in the sub-scanning direction, a red filter is formed on a specific line i + 4 in the main scanning direction of the original, that is, Y coordinate Yi + 4 = Yi + 4 × A × P on the original. At the same time when the light receiving section R reads, a specific one row j + 4 in the main scanning direction, that is, the Y coordinate Yj + 4 = Yj + on the document is read.
4 × A × P is read by the light-receiving unit G having a green filter, and a specific row in the main scanning direction k + 4, that is, Y coordinate Yk + 4 = Yk + 4 × A × P on the original is formed as a blue filter. The light receiving unit B reads.

By sequentially performing the paper feeding operation for each line, the Y coordinate group on the original read by the light receiving section R having the red filter is Yi + A × P × 2 × n, and the light receiving having the green filter is received. The Y coordinate group on the original read by the section G is Yj + A × P × 2 × n ₁ = Yi + A × (DRG + P × 2 × n
₁ ), the Y coordinate group on the original read by the light receiving unit B having the blue filter is Yk + A × P × 2 × n ₂ = Yi + A × (DRG
+ DGB + P × 2 × n ₂ ).

Generally, when an original is read while being thinned out in the sub-scanning direction and an operation for lowering the resolution in the sub-scanning direction is performed, for example, when thinning to M times (M is an integer), the CC
The Y coordinate group on the original read by the light receiving unit R on the CCD of the D color linear solid-state imaging device is Yi + A × P × M × n, and the Y coordinate group on the original read by the light receiving unit G is Yj + A × P × M ×
n ₁ = Yi + A × (DRG + P × M × n ₁ ) = Yi + A × P ×
(nRG + M × n ₁ ), the Y coordinate group on the document read by the light receiving unit B is Yk + A × P × M × n ₂ = Yi + A × (DRG + DGB + P
× M × n ₂ ) = Yi + A × P × (nRG + nGB + M × n ₂ ).

[0016]

However, in the above-described conventional configuration, when the original is read by thinning out the sub-scanning direction by M times, the inter-row distance DRG of the three light-receiving portions of the CCD color linear solid-state image pickup device is read. = NRG × P and DGB = n
In the setting of GB × P, if nRG and nGB are not multiples of M, all Y coordinate groups on the original read by the light receiving units of three rows cannot be represented in the form of Yi + A × P × M × n (n is an integer). There is a problem that color shift occurs because the Y coordinate groups on the document read by the light receiving units of the three rows do not match.

The present invention solves the above-mentioned conventional problems, and the line positions of the document read by the light receiving portions R, G, and B even when the original is thinned out in the sub-scanning direction for reading. It is an object of the present invention to provide a CCD color linear solid-state image pickup device which does not cause color misregistration.

[0018]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a CCD color linear solid-state image pickup device in which the line intervals of the light receiving portion R, the light receiving portion G, and the light receiving portion B are set in the original sub-scanning direction. The configuration is determined from the thinning rate.

[0019]

According to the present invention, even when the original is thinned out in the sub-scanning direction for reading, the light receiving portions R, G, and B match the positions on the original to be read, so that no color misregistration occurs.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of the configuration of a CCD color linear solid-state image pickup device on a CCD according to an embodiment of the present invention. In the figure, R, G and B are main scanning in which red, green and blue filters are formed, respectively. A light receiving portion parallel to the direction X, P is a pixel pitch of the light receiving portion in the main scanning direction.

According to the present invention, the pitch of the light receiving portion intervals of the three rows is a multiple of 6 of the pixel pitch of the light receiving portion in the main scanning direction, that is, DRG = DGB = 6 × N × P (N is an integer). Characterize.

As an example, a case where the pitch of the light receiving portion intervals of three rows is a multiple of 6 of the pixel pitch of the light receiving portions in the main scanning direction, that is, DRG = DGB = 6 × P, will be described. The operation when reading without doing is the same as that of the conventional example. That is, the reading original in FIG. 2 is irradiated with light, and the reflected image is reflected by a reduction lens of magnification A in C in FIG.
An image is formed on the CCD of the CD color linear solid-state image pickup device and a reading operation is performed. In this case, the R, G, and B light receiving portions of the same Y coordinate group (Yi + A × P × n) on the document are used. Read, the same as the conventional example.

However, when the original is read while being thinned out in the sub-scanning direction, and the operation for lowering the resolution in the sub-scanning direction is performed, the operation is different from that of the conventional example, and the color misregistration does not occur. As an example, the operation when the thinning is doubled will be described.

First, a specific row i in the main scanning direction, that is, a Y coordinate Yi on the original is read by a light receiving portion R formed with a red filter, and at the same time, a specific row j in the main scanning direction, that is, on the original. Y-coordinate Yj = Yi + 6 × A × P is read by the light-receiving unit G having a green filter, and a specific row k in the main scanning direction, that is, Y-coordinate Yk = Yi + on the document.
12 × A × P is read by the light receiving unit B having a blue filter.

Next, the original is arranged in two lines in the sub-scanning direction, that is, two lines.
After the paper has been fed by a distance of × A × P, one specific row i + 2 in the main scanning direction of the original, that is, the Y coordinate Yi + 2 = Yi on the original.
At the same time as + 2 × A × P is read by the light receiving unit R having a red filter, a specific row j + 2 in the main scanning direction, that is, Y coordinate Yj + 2 = Yi + 8 × A × P on the original is formed as a green filter. The light receiving section G reads and reads a specific line k + 2 in the main scanning direction, that is, the Y coordinate Yk + 2 = Yi + 14 on the document.
XA * P is read by the light receiving unit B having a blue filter.

Further, after feeding the original by two lines in the sub-scanning direction, a specific line i + 4 in the main scanning direction of the original, that is, the Y coordinate Yi + 4 = Yi + 4 × A × P on the original is formed with a red filter. At the same time when the light receiving unit R reads, a specific row j + 4 in the main scanning direction, that is, the Y coordinate Yj + 4 = Yi + on the document
10 × A × P is read by the light receiving part G having a green filter, and a specific one row k + 4 in the main scanning direction, that is, Y coordinate Yk + 4 = Yi + 16 × A × P on the original is formed as a blue filter. The light receiving unit B reads.

By sequentially performing the paper feeding operation for every two lines in the sub-scanning direction in this manner, the Y coordinate group on the document read by the light receiving portions R, G, B formed with red, green and blue filters. Is the same as Yi + A × P × 2 × n, and no color shift occurs.

Similarly, when the original is read by thinning it in the sub-scanning direction by three times, the paper feeding operation is sequentially performed every three lines in the sub-scanning direction, so that the red, green, and blue filters are formed. The Y coordinate group on the original read by the sections R, G, and B is the same as Yi + A × P × 3 × n, and no color shift occurs.

With such a structure, color misregistration does not occur even if the thinning operation which is frequently used such as double or triple in the sub-scanning direction of the original is performed.

Further, in the above embodiment, the pitch of the light receiving portion intervals of three rows is set to be a multiple of 6 of the pixel pitch of the light receiving portions in the main scanning direction for simplification. Since all the Y coordinate groups read by the light receiving unit of No. 1 match, no color shift occurs.

This will be explained in more general terms. When the original is read by thinning it by M times in the sub-scanning direction, the Y coordinate group on the original read by the light receiving unit R is Yi + A × P × M ×.
n, the Y coordinate group on the original read by the light receiving unit G is Yi + A ×
P × (nRG + M × n ₁ ), Y on the original read by the light receiving unit B
Since the coordinate group is Yi + A × P × (nRG + nGB + M × n ₂ ), the line-to-line distance DRG between the light receiving portion R and the light receiving portion G in the sub scanning direction Y
Is divided by the pixel pitch P in the sub-scanning direction of the light receiving section, and the line spacing DGB between the light receiving section G and the light receiving section B in the sub-scanning direction Y is divided by the pixel pitch P in the sub scanning direction of the light receiving section. If nGB is the integer multiple of the thinning rate M, then red,
The Y coordinate groups on the original read by the light receiving units R, G, and B formed with the green and blue filters are all expressed in the form of Yi + A × P × M × n and coincide with each other, so that no color shift occurs. .

In the present embodiment, the arrangement of the three rows of light receiving portions of the CCD color linear solid-state image pickup device is in the order of R, G, B. However, the order of G, R, B or R, B, G is also possible. Good.

Further, in this embodiment, the case where the color of the color filter is red, green and blue is shown, but the combination of different colors such as yellow, cyan and magenta may be used.

[0035]

According to the present invention, as is apparent from the above embodiments, the pitch of the pixel row intervals of the three light receiving portions of the CCD color linear solid-state image pickup device is set to the pixel pitch of six in the main scanning direction of the light receiving portions. By adopting the multiple structure, even if the commonly used thinning operation such as 2 times or 3 times in the sub-scanning direction of the original is performed, the line positions of the original read by the light receiving portions R, G, and B can be changed. They match and no color shift occurs.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a CCD color linear solid-state image pickup device of the present invention and reading a signal on the CCD.

FIG. 2 is a schematic diagram showing an example of a document read by a CCD color linear solid-state imaging device.

FIG. 3 is a schematic view showing an example of a conventional CCD color linear solid-state image pickup device and related to signal reading on the CCD.

[Explanation of symbols]

R ... Light receiving portion formed with a red filter, G ... Light receiving portion formed with a green filter, B ... Light receiving portion formed with a blue filter, P ... Pixel pitch in the main scanning direction of the light receiving portion,
DRG ... Row spacing between light receiving section formed with red filter and light receiving section formed with blue filter, DGB ... Row spacing between light receiving section formed with green filter and light receiving section formed with blue filter, X ... Main scanning Direction, Y ... sub-scanning direction, i
-4, i-3, i-2, i-1, i, i + 1, i + 2
i + 3, i + 4 ... Rows on the document read by the light-receiving unit formed with a red filter, j-4, j-3, j-2, j-
1, j, j + 1, j + 2, j + 3, j + 4 ... Rows on the document read by the light-receiving unit formed with a green filter, k−
4, k-3, k-2, k-1, k, k + 1, k + 2, k
+3, k + 4 ... Rows on the document read by the light-receiving unit formed with a blue filter, Yi, Yj, Yk ... Y coordinates corresponding to the positions of i, j, k.

Claims (1)

[Claims] 1. A light receiving section having three rows parallel to the main scanning direction, and a pixel row interval pitch of the light receiving sections of the three rows in the sub-scanning direction is 6 pixel pitches in the main scanning direction of the light receiving section. A CCD color linear solid-state imaging device characterized by a multiple.